A gang of 21 Iraqi militants accidentally set off their own car bomb as they were making a promotional propaganda video about a would be suicide bomber.

The explosion left all 21 dead and resulted in two dozen arrests at the camp outside Samarra, a Sunni city 95 kilometers (60 miles) north of Baghdad, Iraqi officials said.

In the city of Mosul to the north, meanwhile, the speaker of parliament - one of the most prominent Sunni officials in Iraq - escaped unhurt from a roadside bomb attack on his motorcade.

A gang of 21 Iraqi militants accidentally set off their own car bomb as they were making a promotional propaganda video about a would be suicide bomber. Police say the camp outside Samarra, a Sunni city 95 kilometers (60 miles) north of Baghdad, was in an orchard in the village of al-Jalam

Car bombs are one of the deadliest weapons used by the al-Qaida breakaway group in Iraq that dominates the Sunni insurgency in Iraq, with coordinated waves of explosions regularly leaving scores dead in Baghdad and elsewhere across the country.